jhp012

I have a 2006 Boxster S and it tells me to put 30 psi in front and 37 psi in back.

Ive noticed the tires can feel very different depending on the outside temperature.

For instance I filled up the tires to spec a week ago when it was in the 40's then here in NJ the weather went to 90s then dropped back to 60s.

Tires felt to hard when in 40's felt really perfect for 2- 3 days during the 90s. then became very mushy when it hit 60s.

I stopped by the gas station yesterday when it was in the 60's to put in more air.

But the meter tells me that the tires are still 30 up front and 37 in the back.

What is going on???? should i up the psi when the temperature is hot or cold?

Kamron

Recommended tire pressure is the cold pressure. It should be higher after the tires have warmed up (i.e., the car has been driven); I don't think outside temps matter as much as the fact that it looks like you're driving the car before you're measuring the pressures; so, your readings aren't accurate.

jhp012

i go straight to the gas station in the morning which is maybe .2 miles away.

Penforhire

You might also be noticing the effect of temperature on behavior of sporty tires. I don't know yours but a lot of sticky tires don't feel right in cold weather unless they get warmed up. The OEM AP1 S02's were like that.

GinoGT

Most high performance tires are notorious for getting stiff in colder weather (40*F). I know my OEM 050's seem to get pretty hard in colder weather.